Bato (voiced by Richard McGonagle[1]) is a member of the Southern Water Tribe and a close friend of Katara and Sokka's father, Hakoda. He is something of a paternal figure to Katara and Sokka in their father's stead and obviously cares about their well-being.[2]

Chey (voiced by John Kassir[1]) is a former soldier from the Fire Nation with the distinction of being the second person to desert from the army and survive.[3] He eventually became disenchanted with the cause of the Fire Nation cause and is now dedicated to fight for the resistance. Wanted posters of him are posted throughout, as seen in "The Deserter" and "The Desert."

Chief Arnook (voiced by Jon Polito[1]) is the Chief of the Northern Water Tribe, and Princess Yue's Father.

Chief Hakoda (voiced by André Sogliuzzo[1]) is the father of Katara and Sokka, the husband of Kya, son of Kanna, and the leader of the Southern Water Tribe.[2] Hakoda is a talented ship captain, igloo builder, and weapon maker. Much of Sokka's ingenuity and craftiness he learned from his father. He went off to war to fight the Fire Nation, leaving his children to be raised by Kanna, his mother.
Fact, from Nicks Avatar cards

"Combustion Man," as he is known to Sokka and his friends, is a firebending assassin/hitman. He was a seemingly silent Fire Nation assassin who served as a major antagonist in the first half of Book 3: Fire, being hired by Prince Zuko to track down and eliminate the Avatar. Utilizing a unique method of Firebending which allowed him to trigger huge explosions at will, he terrorized the Avatar and his friends, following them on their travels across the Fire Nation.

Gran Gran Kanna (voiced by Melendy Britt[1] in the animated series, played by Katharine Houghton in The Last Airbender) is Sokka and Katara's Grandmother, and Hakoda's mother. she originally lived in the Northern Water tribe, but when she was engaged to be married to the arrogant Pakku, she fled south so as not to have to live with the Northern tribe's sexist customs. originally suspicious of Aang, she is given hope when he gives himself up to save the village form Zuko.

In the live-action movie, she is the one who reveals that Aang may be the Avatar to Sokka and Katara.

Guru Pathik (voiced by Brian George[1]) A guru who helps Aang control his Avatar State. he is over 150 years old, and was a Friend to Aang's mentor, Monk Gyatso.

Jet (voiced by Crawford Wilson[1]) is a charismatic teen who holds a deep grudge against the Fire Nation.[6] He was the leader of the Freedom Fighters, who spent their days antagonizing Fire Nation soldiers. Later, he decided to start a new life in Ba Sing Se. Jet uses Twin Tiger-Head Hook Swords as his weapon.
Jet was the teenage leader of a band of Earth Kingdom children called "The Freedom Fighters." The young vigilante held a deep-seated grudge against the Fire Nation for an attack headed by the Rough Rhinos that killed his parents when he was eight. He and his ragtag group spent their days antagonizing Fire Nation soldiers and emigrants on the outskirts of their occupied town, living in forest tree-houses. Jet is marked by his almost pathological hatred of the Fire Nation, being more than willing to kill those of the nation who are not directly involved–a personality trait that IGN critic Tory Ireland Mell called, "a bad message being sent out to a bunch of impressionable young [people] [7]." To him, all citizens of the Fire Nation are guilty, regardless of whether they are involved with the war or not. In some ways he represents what could have happened to Katara and Sokka after the death of their mother; allowing their hatred to consume them. During his stay in Ba Sing Se, Jet was hypnotized and brainwashed by Long Feng after attacking Zuko and Iroh (who both refused to use firebending). Aang and his team helped him overcome the hypnotic state and he and Aang worked together to defeat Long Feng. During the battle, Jet became mortally wounded and Katara was unable to heal him. He died off-screen.

June (voiced by Jennifer Hale) is a female bounty hunter that owns a male Sirshu called Nyla.

King Bumi (voiced by André Sogliuzzo[1]) is the wild-eyed, eccentric, elderly king of Omashu.[8] As a child, Bumi was a close friend of Aang[9], and is the only person who knew him before The War that is known to still be alive. He has become an old and eccentric man, prone to cackling, snorting laughter at unfunny jokes. Despite his age and his apparent frailty, Bumi is an Earthbending master and quite fit for his old age, himself claiming at one point to be "the most powerful Earthbender you'll ever see". Bumi's eccentricity arises out of the fact that he always keeps his mind "open to the possibilities". As a child, Bumi decided to use the Omashu mail delivery system as a chute ride, for which Aang dubbed him "a mad genius", a name that Bumi seems to appreciate. Although Bumi seems senile, he is in fact a brilliant and patient tactician, willing to wait until the opportune moment to strike to best effect. Bumi acts the same during a quiet, peaceful meal as he does when his city is under attack, and he rarely explains his actions, which tends to infuriate his underlings.

Kya is Katara and Sokka's mother and is the wife of Hakoda. She was born and raised in the Southern Water Tribe. Kya is frequently mentioned throughout the show. Her death, at the hands of a Fire Nation raid on the Southern Water Tribe, had a profound impact upon her children.

Long Feng (voiced by Clancy Brown[1]) is the intelligent and cunning Grand Secretarian of Ba Sing Se, head of the Dai Li, and advisor to the Earth King. In reality, the Earth King is merely a figurehead of Ba Sing Se's government[10], so it is actually Long Feng who holds real power. As Grand Secretariat of Ba Sing Se and the head of the Dai Li, Long Feng is a very influential, charismatic, and power-hungry individual who has the tendency to pop up out of nowhere. He rose from humble origins as a son of a Merchant in the Middle Ring of Ba Sing Se, to become the most feared man in the city.
By appearance, his position grants him a special relationship with the Earth King, but in reality the Earth King is but a figurehead of Ba Sing Se's government, and Long Feng truly holds sway over its privatizing affairs. He utilizes the Dai Li to silence anyone who would disrupt the common peace, secretly imprisoning them under Lake Laogai and using hypnotic tactics to subdue them. This effectively keeps the citizens of Ba Sing Se in blissful ignorance and maintains the illusion that there is no war. He claims to have preserved the last utopian society left on the planet by covering up all knowledge of the war, when in fact, the totalitarian traits of Ba Sing Se's government are marks of dystopia.

Master Pakku (voiced by Victor Brandt[1]) is the Waterbending master and instructor of the North Pole's Northern Water Tribe Class. He is possibly the most powerful non-Avatar waterbender in the world. Dryly sarcastic, and very serious about his art, he is a harsh but effective teacher. Likewise stubbornly set in the customs of his culture, he only taught Waterbending to male tribe members; however, his ways have changed recently after meeting Katara, the granddaughter of his runaway fiancee.

Master Piandao (voiced by Robert Patrick[1]) is the greatest sword master and sword maker in the history of the Fire Nation. He decides to take Sokka under his wing. He is set about to do tasks such as landscape painting and calligraphy, as well as practicing against one of the master's underlings. Piandao believes him to be worthy enough to choose a steel to make his sword. Sokka makes a sword out of a meteorite. When the group leaves, they are given a bag with a Pai Sho piece, the White Lotus tile. As the doors to the master's home close, they notice that the symbol of the White Lotus can be seen surrounding that of the Fire Nation. During the Series Finale, when the group goes to find Iroh, they run into Piandao. They find him near the destroyed outer wall of Ba Sing Se, along with Master Pakku, Jeong Jeong, and King Bumi. It turns out that they are all members of the Order of the White Lotus, and were summoned there by a Grand Lotus, Iroh

Monk Gyatso (voiced by [11]) was a member of the Council of Elders at the Southern Air Temple at least a 100 years ago. He was Aang's guardian and closest friend at the temple. He was a powerful Airbending master. According to Aang, Gyatso was the greatest Airbender alive at the time. Gyatso was noted for his kindness and sense of humor.[12] Though Aang learned Airbending under him as part of his Avatar training, Gyatso always allowed time for fun and games. Gyatso also had a strong friendship with the previous Avatar, Roku.

Pipsqueak (voiced by Sterling Young) is a member of the Freedom Fighters. Unlike his name he is actually a huge guy, being the hugest of the Freedom Fighters.

Princess Ursa (voiced by Jen Cohn[1])Is Prince Zuko and Princess Princess Azula's mother, who, throughout the series, is thought to be dead, but was banished by her husband, Fire Lord Ozai, for her treason, to save Zuko's life.

Smellerbee (voiced by Nika Futterman[1]) One of the members of Jet's freedom fighters who is sometimes mistaked as a boy but is actually a girl.

Sozin's dragon is a blue dragon that Fire Lord Sozin used as a mount. It is presumed that Sozin's relationship with the dragon was much like Roku's relationship with Fang, though it is also possible he enslaved it, it was only a pet, or it was only a beast-of-burden.

Avatar Kyoshi was a previous incarnation of the Avatar, born into the Earth Kingdom. She was the Avatar immediately preceding Avatar Roku, 412 years before the start of the series. Kyoshi was a gigantic woman, possessing the largest feet of any Avatar, and lived to be 230 years old, also giving her the title of oldest Avatar. Her traditional weapons were golden metal fans which, in addition to her manner of dress and style of fighting, were adopted by the young warrior women of Kyoshi Island, her homeland.

Avatar Kuruk was a previous incarnation of the Avatar. He was the last Avatar from the Water Tribe before the birth of Aang. He was succeeded by Kyoshi, and died 400 years before the events of the series. Kuruk was a gifted, cocky Avatar who professed to having a "Go with the flow" attitude to his position. This attitude had major consequences for Kuruk, who lost his wife to the spirit Koh because of it.

Avatar Yangchen was the Avatar incarnate born out of the Air Nomads before Aang. She first appears in "The Avatar State". However, only a glimpse of her performing a powerful Airbending move is revealed. She is properly introduced in the online game, Escape from the Spirit World.

The Unnamed Fire Avatar was an Avatar who hailed from the Fire Nation centuries before the war. He appeared in "The Avatar State" when Avatar Roku was telling Aang more about the Avatar State. He was seen briefly, making volcanoes erupt by using his Firebending, and possibly his Earthbending, enhanced by the Avatar State.